Aha, I figured it'd be a matter of time before you'd piece together some stuff from all the 1x1 I'm running. I won't spoil too much, but here's what Talogan will know with a rudimentary education in life.

The world is surrounded by this incredibly dense fog, often on the other side of a large mountain range. This is also why there's a dent in the north east, as the mount range does not form a fully perfect circle.

Secondly, so far no one who has ventured directly into the fog as ever returned. Many heroes have tried, millions of gold spent on expedition, magic equipment, and all sorts of planar and teleportation devices, but once you go into the fog you're never heard from again. most nations have simply chosen to never explore further than the peaks of the mountains for the sake of their own resources.

Lastly, it's generally believed that the world was not always like this. While there's massive debates between scholars, religious figures, scientists, and mages, the collective consensus was that at some point long before their earliest writings, the world was not like this at all. The Mana Storms, which I told you about previously, is widely believed to be connected to the phenomenon that is the world's geography. Astronomers are certain that the sun operates within an orbit, implying that the world is truly round, or at least that the sun revolves around it in a consistent pattern, creating a typical day/night cycle with varying degrees of solstices. And planar travelers have confirmed that they have traveled to other worlds and found that their worlds are round as well, circumventing their globe in a linear journey.

So why is Keratia flat, surrounded by giant mountains surrounded by fog? No one knows. Not yet at any rate.